The present invention relates generally to an enhanced inertial sensor system.
Occupant restraint systems and vehicle dynamics control systems (like Electronic Stability Control) typically use inertial sensors such as accelerometers and gyroscopes to detect events that warrant operation of the various restraining/stabilizing actuators. Occupant restraint systems typically need to sense relatively large, abrupt changes in acceleration and/or rotational rate over a short time period. Vehicle dynamics control systems typically need to sense comparatively smaller, subtler changes in acceleration and rotational rate over a longer time period. Selecting a single accelerometer and/or single rotational rate sensor that can measure the larger signals required by a restraint system, and is also capable of accurately measuring the smaller signals required by the vehicle dynamics control system, is typically difficult because the gain and offset errors of the large signal sensors are often greater than the requirements for stability control systems. Minimizing the gain and offset errors in the accelerometers and gyroscopes through sensor improvements alone, or individual calibration, often becomes cost prohibitive.